ES2924647T3 - fan spray device - Google Patents

Abstract

The invention relates to a novel fan spray device (10) comprising a housing having an electrically driven fan and a spray nozzle, and comprising a liquid supply line (21) leading to the spray nozzle. (twenty). The casing (16) has a funnel-shaped suction channel (17) and a tubular blowing channel (18), and an electric valve (22) is provided in the liquid supply line (21) to enable and disable the liquid supply to the spray nozzle (20). Furthermore, an electronic controller (28) comprising a control unit (33) for the electric fan (19) is provided to set the air flow speed. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

fan spray device

TECHNICAL AREA

The invention relates to a fan spray device according to the preamble of claim 1 and to a method for generating a spray mist with said fan spray device according to the preamble of claim 15.

STATE OF THE ART

Fan spray devices of this type, known as motor sprayers, are used, for example, in plant protection in agriculture or horticulture, for pest control.

Such an engine-driven sprayer essentially consists of a back-mounted spray tank, a gasoline engine and a fan, and is known, for example, from CH-A-327997. An air filter connects before the fan intake chamber and the fan pressure chamber connects to a wide compressed air hose as well as a narrower air supply line. This conduit opens with its other end slightly above the bottom of the spray agent container, so that the compressed air escaping stirs up the spray liquid in the container. The exhaust air leaves the container through an exhaust duct. At the outlet end of the compressed air hose there is an atomizing nozzle, to which a spray liquid supply line and the exhaust air line are connected. To date, these engine sprayers have been powered by gasoline engines, which are relatively noisy and produce exhaust fumes. Another disadvantage of gasoline engines is the insufficient ability to adjust the speed of the air flow. This circumstance is justified by the principle of operation of motor sprayers of this type. Without high air discharge velocity, current motorized sprayers would not be able to atomize the supplied spray liquid. However, these high air velocities can cause plant damage. Furthermore, it may happen that the active ingredient is sprayed beyond the plant as a result of high air velocity and does not accumulate on the plant.

In order to obtain a better atomization of such a motorized sprayer, DE-A-102012012800 describes a spraying device for a handheld fan, comprising an arrangement of air ducts and a spray agent nozzle, in where the air duct arrangement extends along a longitudinal axis that determines the spray direction. The air duct arrangement comprises two outlet duct sections in which the blowing air flow is divided into two partial air flows exiting the two air nozzles. The two sections of the outlet duct open into two air vents arranged side by side in the lateral direction relative to the longitudinal axis, in such a way that an air flow-free space is formed between the two partial air flows. . The spray agent nozzle is located in the airflow clearance, where, by means of the spraying agent nozzle, an atomized spray agent is introduced in the form of droplets into the airflow clearance. The air flow speed of the two partial air streams is in the range from 30 m/s to 120 m/s, preferably 70 m/s. The speed of the atomized spray droplets is in the range of 2 m/s to 40 m/s, preferably 10 m/s. The spray pressure is in the range from 2 bar to 15 bar, preferably 5 bar. When the partial air streams and the atomized spray agent meet, a mixture is generated having a flow velocity of 10 m/s to 80 m/s, in particular 40 m/s.

The above motorized sprayer has the same disadvantages as described above.

KR-A-20120056541 discloses a portable sprayer with a reservoir, an electric pump, a long blow tube with a fan directly at the inlet and a spray nozzle directly ahead of the blow tube outlet. The blow tube has a constant diameter throughout its length. The spray nozzle is connected to the tank by a hose. There is also a lever on the blow tube with which a manually operated valve on the hose can be opened and closed. On the one hand, the pump motor is connected to the positive pole of a battery through a pump control and operation switch, and on the other hand, the fan motor is connected to the positive pole of the battery through of a fan control and operation switch. This operation switch is located on the blow tube lever. In addition, on the negative pole of the battery there is a switch for pressure, which is electrically connected to the pump control and the fan control. This pressure switch is attached to the pump. If the pressure in the pump is too high, the switch trips so that the pump control and fan control are disconnected from the battery. The fan and the pump are connected and disconnected by means of a simple pressure switch. This sprayer does not include air speed or spray pressure adjustment.

OBJECTIVE OF THE INVENTION

The present invention is now based on the object of providing a portable blowing spray device which allows an efficient and environmentally friendly use of the spraying agent and a homogeneous spray pattern. It is a further object of the invention to disclose a method for generating a spray mist with such a fan spray device.

These objects are achieved by a fan spray device with the features of patent claim 1 and by a method for generating a spray mist with the features of patent claim 15.

The present invention is based on the realization that only the interaction of an adjustment of the speed of the air flow and an adjustment of the pressure of the spray medium, with a correct selection of the nozzle of the spray medium, leads to the pattern of desired spray of the spray mist to be produced. However, the spray pressure can also be preset if the scope of application is restricted.

The invention has the advantage of producing a defined spray pattern of the spray mist, in which the fan spray device operates with an adjustable air flow rate. Another advantage of the invention is that the blowing spray device can be precisely adapted to the different requirements of the respective applications by accurately controlling the air velocity and adjusting the spray amount and droplet size by choosing a proper nozzle and pressure. The blown spray device according to the invention allows, through the correct selection of the mentioned parameters and the limitation of the influencing variables, to comply with the spray pattern required by a given application much better than with the currently known procedures of the technology. spray blowing. In this case, the air flow is only necessary to transport the droplets in the spray mist, but not for the formation of the droplets.

The spray blowing device according to claim 1 is provided with a casing comprising an electrically driven fan with a paddle wheel and a spray nozzle, and having a liquid supply conduit opening into the spray nozzle, the casing having a funnel-shaped intake duct and a tubular discharge duct, and in the tubular discharge duct there are guide vanes located after the impeller in the direction of flow, said guide vanes being configured and arranged in such a way such that the turbulence generated by the paddlewheel is converted into a smooth, eddy-free or approximately eddy-free airflow in the axial direction. The spray nozzle is arranged along the longitudinal axis in the discharge duct, so that the swirl-free or almost swirl-free airflow envelops the spray mist coming out of the spray nozzle. And in the liquid supply line there is an electrically operated valve to turn the liquid supply to the spray nozzle on and off. In addition, an electronic control with a regulation unit for the electric fan is provided.

It is advantageous if the electric fan according to claim 2 is arranged in an elongated, tube-shaped housing which at the same time serves to mechanically fix the spray nozzle.

In this connection, it has been found useful to float-mount the electric fan or spray-blowing units according to claim 3 and to store them in the casing.

Advantageously, the fan according to claim 4 is mounted in the discharge duct and the spray nozzle is arranged in the flow direction at a first distance from the fan in the discharge duct and at a second distance from the outlet of the discharge duct.

According to claim 5, the inlet duct advantageously has an inlet opening with a first large cross section and an outlet opening with a second smaller cross section.

In a preferred embodiment of the fan spray device according to claim 6, the spray nozzle is a full cone nozzle.

In another preferred embodiment of the fan spray device of claim 7, the spray nozzle is a hollow conical nozzle.

In another preferred embodiment of the fan spray device of claim 8, the spray nozzle is an injection nozzle.

In another preferred embodiment of the fan spray device according to claim 9, the spray nozzle is a flat jet nozzle.

In another preferred embodiment of the fan spray device according to claim 10, the spray nozzle is a multi-substance nozzle.

In another preferred embodiment of the fan spray device of claim 11, the spray nozzle is a piezoelectric ultrasonic atomizer.

In another preferred embodiment of the fan spray device of claim 12, the spray nozzle is a rotating disk.

According to claim 13, the fan spraying device is preferably portable.

However, the fan spray device can also be mounted on a chassis according to claim 14.

In the method of generating a spray mist according to claim 15 with a blowing spray device according to the invention and a sprayer with pressure control, a spray liquid is selected for the corresponding application and the nozzle is determined from a selection of spray nozzles. The nozzle is selected for the application based on pressure, spray angle, flow rate and droplet size. The spray liquid is then pressurized to a pressure set for the application and/or the fan airflow selection and speed are set for the application.

DESCRIPTION OF THE INVENTION

Further advantages of the invention will emerge from the dependent patent claims and the following description, in which the invention is explained in more detail with reference to an example of an embodiment shown in the schematic drawings. It shows:

Fig. 1 a battery-powered backpack sprayer with a blowing spray device in perspective view on one half of the housing,

Fig. 2 an enlarged representation of the fan spray device from Fig. 1,

Fig. 3 a cross section through a second embodiment of the fan spray device, Fig. 4 the fan spray device from Fig. 3 in perspective view,

Fig. 5 the spray blowing unit in perspective view,

Fig. 6 a cross section of the blowing unit from Fig. 5,

Fig. 7 a representation of the distribution of the speed of the air flow at the outlet of the spray nozzle (injection),

Fig. 8 the flow pattern from the rotating airflow generated by the paddlewheel to a uniform, eddy-free airflow transferred by the guide vanes,

Fig. 9 a perspective diagram of the air flow through the entire fan spray device, and Fig. 10 a perspective view of the air flow shown in figure 8.

In the figures, the same reference symbols have been used for each of the same elements and the explanations of the first time apply to all figures, unless expressly indicated otherwise. Fig. 1 shows a battery-powered backpack sprayer 1 from the company Birchmeier Sprühtechnik AG, CH-5608 Stetten, which is marketed under the name REC 15. This sprayer 1 has a liquid reservoir 2, an air reservoir 3, a electric pump 4 and a battery or accumulator 5. In the air tank 3 there is a pressure sensor 6, which is connected to a pressure regulator 7 in the backpack sprayer 1. With the pressure regulator 7 the pressure can be adjusted to the spray liquid. A liquid supply line 8 is also connected to the air container 3, which is removably attached to a portable fan spray device 10 by a connection 9. In addition, the fan spray device 10 is connected to the battery 5 via an electrical cable 11 with an electrical connector 12.

In Figure 2, the fan spray device 10 is shown in an enlarged view with the front half of the casing removed so that only the rear half 15 of the casing 16 is visible. The casing 16 has an intake duct in the form of a funnel 17 and a tubular exhaust duct 18. An electric fan 19 with a paddle wheel 38 is completely surrounded by the wall of the casing and fixed in the outlet duct 18. To reduce vibrations and noise from the engine , the electric fan 19 can be floatingly mounted and or supported on the discharge duct 18, as described in more detail below for the second form of embodiment of the fan spray device. In the discharge duct 18 there are arranged, inside the casing wall, some guide vanes -not shown here- which are arranged in the axial direction of the discharge duct 18 in the flow direction A, downstream of the impeller 38. These guide vanes can have a small angle of up to 10° with respect to the direction of the axis. These guide vanes convert the turbulence generated by the impeller 38 into a swirl-free, or nearly swirl-free, airflow. In flow direction A, downstream of the electric fan 19, a spray nozzle 20 is mounted in the discharge duct 18, which is connected to a liquid supply line 21 and an upstream electrically operated valve 22. Valve or solenoid valve 22 can be used to connect the flow of spray liquid. The spray nozzle 20 is mounted at the front end of a mounting tube 23, which is attached to the casing 16 by means of four brackets 24, in such a way that between the mounting tube 23 and the inner wall of the discharge duct 18 is an open annular space 25. Spray nozzle 20 is mounted at the forward end of mounting tube 23 so that pre-atomization occurs when spray liquid exits spray nozzle 20. The size of the drop can be adjusted by selecting a suitable nozzle and pressurization. Also, in the casing 16 there is an electric cable 27 with an electronic control 28 for the fan 19. The control 28 can be used to adjust the speed of rotation of the fan 19, that is, the speed of the air. The housing 16 further comprises an angled handle 30 in which the fluid supply line 21 and the valve 22 are located. In the angular area 31 of the handle 30 there is a switch 32 for the valve 22 and a regulation unit 33 for control 28, with which the exact rotational speed of fan 19 can be set. Control unit 33 can be an analog rotary knob, or it can include digital adjustment.

The spray nozzle 20 is now arranged at a distance d1 from the outlet side of the fan 19. The spray nozzle 20 has an orifice 26 and the discharge duct 18 has an outlet 29. The spray angle is mainly determined by the choice of the spray nozzle 20. The orifice 26 is located inside the discharge duct 18 at a distance d2 from the outlet 29 so that the spray mist cannot wet the wall of the discharge duct 18 and so that it can form no obstacles.

The funnel-shaped inlet duct 17 has an inlet opening 35 with a large cross section B and an outlet opening 36 with a smaller cross section C. The ratio of the large cross section B to the small cross section C is optimally configured, in terms of flow technology, to allow air to exit the fan outlet with a flow speed of approximately 5 m/s to 120 m/s.

The inlet opening is selected to be sized so that it is large enough so that the inlet velocity is low at the outlet flow velocities that normally occur, and therefore so that the risk of suction ( leaves, etc). In this case, the ratio is 1:4, but it can also be smaller or larger.

The spray nozzle 20 is arranged in this case with the mounting tube 23 in the center of the discharge line 18. However, it can also be arranged decentrally or directly on the inner wall of the discharge line 18. The spray nozzle spray 20 is selected from a wider range of nozzles depending on the application. A full cone nozzle, a hollow cone nozzle, a flat spray nozzle and an injection nozzle have proven to be suitable spray nozzles. A rotating disk, multi-fuel nozzle or piezoelectric ultrasonic atomizer can also be used.

The aforementioned portable fan spray device 10 now allows fine adjustment of the desired spray pattern for the spray to be produced by allowing the pressure of the supplied spray liquid, the velocity of the discharged air flow, and the pre-atomization are precisely adjusted by a correct selection of several spray nozzles 20. This means that less chemical spray liquid is needed, for example for crop protection. In particular, it has been found that too high an air velocity causes damage to crops of sensitive plants and/or that plants experience insufficient wetting of their leaves. With a lower air speed, the leaves of the plants are only swirled, so that optimal wetting of the leaves occurs without damaging the crop. In addition, by selecting the proper nozzle, droplet size can be adjusted to minimize aerosol formation or spray mist drift or to achieve long range spray mist.

In practice, the backpack sprayer 1 with the pressure regulator and the blowing spray device 10 is used, and the necessary electric power is supplied by means of the battery 5. However, it is also possible to use a backpack sprayer without pressure regulator, in which case the possible applications are limited or the result is not optimal. On the other hand, a sprayer placed on a non-powered or powered chassis can also be used, in which the fan-spray 10 is fixed, can be adjusted in the X, Y and/or Z direction and/or is mounted in a fixed manner. pivoting on the chassis. In this case, multiple fan spray devices 10 or fan spray units 40 can also be used. When multiple fan spray devices 10 or fan spray units 40 are used, the power supply and spray liquid spraying can be centralized, with the possibility of individual adjustment of each fan spray device 10 or fan spray unit 40.

In addition, the generated spray mist can be optimally introduced into the correct airflow. This requires several electronic control units. For example, an electronic control unit can be provided which ensures that the spray liquid is not introduced into the air jet until the set air flow rate has been reached. An electronic control unit can also be provided which serves to ensure that the spray liquid is introduced based on the speed of the airflow, which means that the spray liquid is only introduced into the airflow after a certain amount of time. time delay or less spray liquid is introduced when airflow speed is reduced. In addition, the spray liquid supply can be completely stopped for a certain amount of time in advance before the speed of the air flow throttles or stops. This prevents the spray liquid from dripping.

Figures 3 and 4 show a cross-sectional view of a second embodiment of the fan spray device 10. Items that are the same are indicated by the same reference symbols as in Figure 2. The electric spray unit is shown here with the reference symbol 40. The electronic control 28 is provided with a heat sink 41, which is embedded in a corresponding opening of the intake duct 17. The funnel-shaped intake duct 17 has a substantially larger cross section in this area than the cross section in the exhaust duct 18, so that a larger cooling surface is available here that can be used, so that very effective cooling of the electronic control 28 is achieved by the heat sink 41. In addition, in this case the air speed is lower. Compared to cooling with fast blowing air in the exhaust duct 18, a greater noise reduction is achieved.

The inlet opening of the intake duct 17 is provided with a grill 39 so that it is not possible to accidentally insert a hand into the intake duct 17. In addition, the paddle wheel 38 is far enough away from the inlet opening to prevent injury. .

Figures 5 and 6 show the spray fan unit 40 with the impeller 38 in more detail.

The essential difference with respect to the first embodiment of FIG. 2 is that the fan 19 is arranged in a roughly elongated housing 42, which at the same time serves for the mechanical fixing of the spray nozzle 43. The housing 42 has a annular inlet lip 44. The air is sucked in optimally through the inlet lip 44, so that a significant noise reduction is achieved. On the inner wall 45 of the casing 42 there are two guide vanes 46, facing each other and aligned substantially parallel to the axial direction A. These guide vanes can also have a small angle of up to about 10° with respect to the axial direction. . These guide vanes 46 can also be streamlined like a wing. The electric drive 47 is located behind the impeller 38. The mounting 49 of the spray nozzle 43 is now designed in such a way that it is in the slip current of the electric drive or motor 47, so that it cannot be disturbed. the uniform and vortex-free or approximately vortex-free airflow generated by the guide vanes 46. To this end, the suspension 50 of the closure 49 in the housing 42 is also provided in a rounded and curved shape. This suspension 50 is designed very flat so that annoying turbulence does not occur.

In order to minimize the transmission of vibrations from the fan 19 to the casing 16, the casing 42 is floatingly mounted on the casing 16. To this end, on the outer wall of the casing 42 there are two opposite transverse bands 52, which are surrounded by a cuboid damping element 53 of a suitable flexible material, such as rubber. The inner wall of the casing 16 (see figure 3) surrounds the damping element 53 with a contour with punctual supports -not shown-, in such a way that the transmission of sound and vibrations by the electric drive 47 is counteracted, the paddle wheel 38 and the air turbulence in the spray fan group 40.

The spray nozzle 43 is configured in the form of an elongated tube 55 with a nozzle outlet 56, having a connecting nozzle 57 into which the supply line 58 is connected. Figure 7 shows the diagram of the distribution of the velocity of the outgoing air at the outlet of the nozzle 56. The dark ring 60 around the outlet of the nozzle 56 indicates that there is practically no airflow in the slipstream of the electric drive or motor 47, so that the spray mist can be formed without hindrance. The gray area 61 shows that a strong airflow is produced here which collects the spray mist coming out of the nozzle outlet 56 and thus prevents the droplets from escaping from the airflow to the outside and being lost in the application. . This explanation applies to both described embodiments of the spray blowing device 10.

Figure 8 is a representation of the air flows by means of flow lines in the area of the impeller 38 and in the area of the guide vanes 46. It follows that the air flow rotating through the wheel The vane 38 is converted by the guide vanes 46 into a uniform swirl-free or approximately swirl-free airflow, ie, an approximately linear airflow in the axial direction. Thanks to this swirl-free or near-swirl-free airflow in the axial direction, a longer spray mist throwing distance can be achieved and with less energy.

Figure 9 shows the air flow by perspective flow lines from the air inlet to the air outlet of the fan spray device 10.

Fig. 10 schematically shows the air flow by means of perspective flow lines in the area of the impeller 38 and the guide vanes 46. This clearly shows that a rotating air flow or turbulence is generated in the area of the paddlewheel 38 - shown here with five paddles 38 - which is converted into a linear vortex-free or nearly vortex-free airflow by means of the four guide vanes 46.

The number of guide vanes 46 can vary depending on the requirements and the configuration of the paddle wheel 38. Generally, the number is three to four, but it can also be five or more. In the above embodiments, five blades 38 are provided. There may also be five to seventeen, depending on requirements and configuration.

Claims (15)

1. Fan spray device (10) having a casing, comprising an electrically driven fan (19) with a paddle wheel (38) and a spray nozzle (20; 43), having a supply line of liquid (21) opening at the spray nozzle (20; 43), characterized in that the casing (16) has a funnel-shaped suction duct (17) and a tubular discharge duct (18), and in the tubular discharge duct (18) guide vanes (46) are provided after the impeller (38) in the direction of flow, which are configured and arranged in such a way that the turbulence generated by the impeller (38) becomes a uniform, swirl-free or approximately swirl-free airflow in the axial direction, and the spray nozzle (20; 43) is arranged in the longitudinal axis in the discharge duct (18) in such a way that the flow of swirl-free air receives the spray mist that exits from the spray nozzle (20), and an electrically operated valve (22) is provided in the liquid supply conduit (21) for turning on and off the liquid supply to the spray nozzle (20; 43), and an electronic control (28) is provided with a control unit (33) for the electric fan (19) in order to adjust the speed of the air flow according to the respective application. 2. Fan spray device (10) according to claim 1, characterized in that the electric fan (19) is arranged in an elongated and tubular casing (42) which at the same time serves to mechanically fix the spray nozzle (43). 3. Fan spray device (10) according to claim 1 or 2, characterized in that the fan (19) is floatingly mounted in the housing (16). 4. Fan spray device (10) according to any one of claims 1 to 3, characterized in that the fan (19) is mounted on the discharge duct (18) and the spray nozzle (20) is arranged in the direction of flow (A) at a first distance (d1) from the discharge side of the fan (19) in the discharge duct and at a second distance (d2) from the outlet of the discharge duct. 5. Fan spray device (10) according to any one of claims 1 to 4, characterized in that the intake duct (17) has an inlet opening (35) with a first large cross-section (B) and an opening of outlet (36) with a second smaller cross section (C). 6. Fan spray device according to any one of claims 1 to 5, characterized in that the spray nozzle (20) is a full cone nozzle. 7. Fan spray device according to any one of claims 1 to 5, characterized in that the spray nozzle (20) is a hollow cone nozzle. 8. Fan spray device according to any one of claims 1 to 5, characterized in that the spray nozzle (20) is an injection nozzle. 9. Fan spray device according to any one of claims 1 to 5, characterized in that the spray nozzle (20) is a flat jet nozzle. 10. Fan spray device according to any one of claims 1 to 4, characterized in that the spray nozzle (20) is a multi-substance nozzle. 11. Fan spray device according to any one of claims 1 to 5, characterized in that the spray nozzle (20) is a piezoelectric ultrasonic atomizer. 12. Fan spray device according to any one of claims 1 to 5, characterized in that the spray nozzle (20) is a rotating disk. 13. Fan spray device according to any one of claims 1 to 12, characterized in that it is portable. 14. Fan spraying device according to any one of claims 1 to 11, characterized in that it is mounted on a chassis. 15. Method for generating a spray mist with a fan spray device according to any one of claims 1 to 14 and with a spray apparatus (1) having a pressure regulation, characterized in that a spray liquid is selected for the respective application, from a selection of spray nozzles a spray nozzle with a certain spray angle and a certain droplet size is selected for the respective application, a pressure adjusted for the application is applied to the spray liquid or the respective selection, and the airflow of the fan (19) is adjusted for the respective application.